Compositional and morphological design of hierarchical Co2Y@MnO2@CNTs core-shell microflowers for broadband microwave absorption application
Compositional and morphological design of hierarchical Co2Y@MnO2@CNTs core-shell microflowers for broadband microwave absorption application
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分级结构Co2Y@MnO2@CNTs核壳结构宽带微波吸收微孔的组成和形貌设计
DOI：
10.1016/j.jallcom.2021.159270
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发表时间：
2021-02
影响因子：
6.2
通讯作者：
Li He;Xun Li;Ruochen Dai;Z. Zhong;Yuchen Zhao;Ying Yang
中科院分区：
文献类型：
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作者：
Li He;Xun Li;Ruochen Dai;Z. Zhong;Yuchen Zhao;Ying Yang
六角铁氧体材料被认为是先进电磁波吸收（EMA）材料的有前途的候选者。同时，由于微波吸收的诱导多重散射和电磁损耗能力，花状形态和分层结构已被广泛认为是实现较低反射损耗（RL）和更宽合格带宽（QB，RL≤-10dB）的关键技术。在这项研究中，通过一种简便的一步水热法成功合成了Co2Y@MnO2@CNTs的核壳纳米结构复合材料，其中Ba2Co2Fe12O22(Co2Y)纳米颗粒包裹在附有空心MnO2微花的碳纳米管(CNT)中。结果表明，通过调节Co2Y和MnO2反应物的质量比可以很好地控制表面形貌，并且通过精确调节导电碳纳米管附件可以大大提高特性阻抗。在 1.0 至 5.0 mm 的集成薄厚度内实现了 15.7 GHz（2.3–18 GHz）的超宽 QB 值，这意味着该复合材料在 S、C、X 和 Ku 频段以相对较薄的样品厚度表现出优异的 EMA 性能。例如，在 Ku 频段，RLmin 在 12.6 GHz 处达到 -22.6 dB，QB 为 7.22 GHz，在 1.63 mm 处；在 S 和 C 频段，RLmin 在 3.28 GHz 处达到 -40.4 dB，在 4.87 mm 处 QB 为 3.47 GHz。除了出色的微波吸收剂候选物之外，这项工作还开发了一种新颖且更通用的方法，通过精细的纳米结构和成分设计来促进基于铁氧体的高性能 EMA 应用。
The hexaferrite materials have been regarded as a promising candidate for the advanced electromagnetic wave absorbing (EMA) materials. Meanwhile, the flower-like morphological and hierarchical structure has been widely accepted as a critical technique to achieve both lower reflection loss (RL) and wider qualified bandwidth (QB, RL ≤ −10 dB) due to the induced multiple scattering and electromagnetic loss abilities for microwave absorption. In this study, core-shell nanostructure composites of Co2Y@MnO2@CNTs have been successfully synthesized by a facile one-step hydrothermal method, in which the Ba2Co2Fe12O22(Co2Y) nanoparticles are wrapped in the carbon nanotubes (CNTs) attached hollow MnO2microflowers. Results show that the surface morphology can be well controlled by modulating the mass ratio of Co2Y and MnO2reactants, and the characteristic impedance can be greatly improved through the precise tuning of the conductive CNTs attachments. An ultra-wide QB value of 15.7 GHz (2.3–18 GHz) is realized within an integrated thin thickness from 1.0 to 5.0 mm, which means the composite shows excellent EMA performance in the S, C, X, and Ku band with relatively thin sample thicknesses. For example, the RLminreached −22.6 dB at 12.6 GHz with a QB of 7.22 GHz at 1.63 mm in the Ku band, and −40.4 dB at 3.28 GHz with a QB of 3.47 GHz at 4.87 mm in the S and C band. Besides the outstanding microwave absorbent candidates, this work has also developed a novel and more generalized approach to promoting the ferrite-based high-performance EMA application by delicate nanostructure and composition design.